Build fails on i386: use of overloaded operator '[]' is ambiguous

[yurivict]

/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:40:38: error: use of overloaded operator '[]' is ambiguous (with operand types 'const inlet::Proxy' and 'const char *')
  auto values = toDoubleVector(parent[fieldName], expectedDims, fieldName);
                               ~~~~~~^~~~~~~~~~
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/inlet/Proxy.hpp:123:9: note: candidate function
  Proxy operator[](const std::string& name) const;
        ^
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:40:38: note: built-in candidate operator[](int, const char *)
  auto values = toDoubleVector(parent[fieldName], expectedDims, fieldName);
                                     ^
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:40:38: note: built-in candidate operator[](int, const volatile char *)
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:52:12: error: no matching function for call to 'toArrayLike'
    return toArrayLike<T>(parent, fieldName, expectedDims);
           ^~~~~~~~~~~~~~
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:69:10: note: in instantiation of function template specialization 'axom::klee::internal::toArrayLike<axom::primal::Point<double, 3> >' requested here
  return toArrayLike(parent, fieldName, expectedDims, defaultValue);
         ^
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:36:3: note: candidate template ignored: substitution failure [with T = axom::primal::Point<double, 3>]
T toArrayLike(inlet::Proxy const &parent,
  ^
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:45:3: note: candidate function template not viable: requires 4 arguments, but 3 were provided
T toArrayLike(inlet::Proxy const &parent,
  ^
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:52:12: error: no matching function for call to 'toArrayLike'
    return toArrayLike<T>(parent, fieldName, expectedDims);
           ^~~~~~~~~~~~~~
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:84:10: note: in instantiation of function template specialization 'axom::klee::internal::toArrayLike<axom::primal::Vector<double, 3> >' requested here
  return toArrayLike(parent, fieldName, expectedDims, defaultValue);
         ^
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:36:3: note: candidate template ignored: substitution failure [with T = axom::primal::Vector<double, 3>]
T toArrayLike(inlet::Proxy const &parent,
  ^
/wrkdirs/usr/ports/science/axom/work/axom-0.6.1/src/axom/klee/IOUtil.cpp:45:3: note: candidate function template not viable: requires 4 arguments, but 3 were provided
T toArrayLike(inlet::Proxy const &parent,
  ^

Version: 0.6.1
OS: FreeBSD 13

[white238]

This seems like a compiler bug. Do you need klee functionality? If not you can turn it off with -DAXOM_ENABLE_KLEE=OFF on your CMake command.

[rhornung67]

Likely. Which compiler and version are you using?

[yurivict]

clang-12.0.1

[yurivict]

Do you need klee functionality? If not you can turn it off with -DAXOM_ENABLE_KLEE=OFF on your CMake command.

This happens in the package build, so turning off options isn't desirable.

[publixsubfan]

The problem appears to be coming from Inlet, specifically this overload:

axom/src/axom/inlet/Proxy.hpp

Lines 79 to 88 in 9d9ff2b

	template <
	typename T,
	typename SFINAE = typename std::enable_if<
	detail::is_inlet_primitive<T>::value || detail::is_inlet_primitive_array<T>::value ||
	detail::is_inlet_primitive_dict<T>::value || detail::is_std_function<T>::value ||
	detail::is_primitive_std_vector<T>::value>::type>
	operator T() const
	{
	return get<T>();
	}

which seems to match with the implicitly-defined operator[](std::ptrdiff_t, const char*) on i386, apparently.

I was able to replicate the error on toss3 by adding std::is_same<T, std::ptrdiff_t>::value to the SFINAE conditional set. We can fix this by adding a operator[](const char* name) overload for the inlet::Proxy class.